1. Field
The invention relates to software installation and, more particularly, to reducing problems in computer system operation related to software installation.
2. Background Information
A software program typically includes a sequence of instructions stored in a memory and executed by a processor. As used herein, the term xe2x80x9cprogramxe2x80x9d may refer to any form of packaging (that is, organizing and grouping) sequences of software instructions. The term xe2x80x9cprogramxe2x80x9d may refer to executable programs, statically-linked libraries, dynamically-linked libraries, applets, and many other forms of packaging and organization for software sequences well known in the art.
An installation program is a program which installs another program on a computer system. A computer system may be any device comprising a processor to execute instructions and a memory to store the instructions. In a computer system, instructions in the memory are typically supplied to the processor by way of a bus. The installation of a program may involve numerous tasks. For example, installation may involve altering or adding to configuration files of the computer system, including files that configure the operating system. Herein, the term xe2x80x9coperating systemxe2x80x9d refers to a sequence of instructions which, when executed by the processor, manages computer system resources. Computer system resources include memory and input/output (I/O) ports.
In addition to modifying configuration files, an installation program may alter or add settings with a central data store for the computer system. On computer systems running the Microsoft Windows(trademark) operating system, the central data store is called the Registry. The installation program may also copy, move, and overwrite files on the computer system.
Alterations to a computer system caused by an installation program may create operational problems for the operating system or other installed programs. For example, the installation of a program designed to cooperate with previously installed programs may result in modifications to the settings for the previously installed program. These setting modifications may cause the previously installed program to operate in abnormal ways. The installation program may copy over or move files on the computer system mass storage device (such as a hard disk). These files may be used by previously installed programs or the operating system. Overwriting or moving them may result in abnormal operation of the programs. In the worst case, the previously installed program or operating system may cease to operate altogether or may operate in a destructive fashion.
On some computer systems, it may be possible to execute an uninstall program to undo some of the effects of installation. However, it may not be possible to undo all of the effects of installing a program. For example, if the installation program overwrote a file used by another program, is may not be possible to recover the overwritten file. Backup copies may be kept of overwritten files, but making and keeping backup copies may be time consuming and may consume space on the computer system""s storage device.
A need therefor exists for a manner of installing programs which enables the effects of the installation to be observed and analyzed before causing actual alterations to the computer system configuration.